Subprojeto 14 – In vivo imaging of interactions between MADS-box transcription factors involved in flower development

MADS-box transcription factors are major regulators of vegetative and reproductive development in flowering plants. These factors act in a combinatorial manner, either as homo- or heterodimers, and these control floral organ formation and identity and many other developmental processes through a complex network of protein-protein and protein-DNA interactions. Despite the fact that many studies have been carried out to elucidate MADS-box protein dimerization by yeast systems, very little information is available on the behaviour of these molecules in planta. Fluorescence Resonance Energy Transfer (FRET) based methods have become a key for the detection of protein-protein interactions in living cells. FRET can be quantified by observing changes in the fluorescence lifetime of the donor using Fluorescence Lifetime Imaging Microscopy (FLIM). This in vivo approach might provide evidence for the in planta assembly of flower-specific MADS-box transcription factors into higher-order complexes and their sub-cellular localization. We have isolated and characterized the expression patterns of MADS-box genes involved in passionfruit (Passiflora spp) flower development. The aim of this project is to obtain information about the specificity of the interactions between MADS-box transcription factors involved in passionfruit flower development and the evolutionary conservation of these interactions when compared to model systems.